1. Field of the Invention
This invention relates to a heat exchanger for use with a fireplace assembly to increase the heat transfer capacity of the fireplace assembly without increasing the flow of ambient air through the heat exchanger or the size of the heat exchanger.
2. Description of the Prior Art
A heat exchanger for use with a fireplace or a fireplace incorporating a heat exchanger is known, for example, as taught in U.S. Pat. No. 4,185,612 of Briner and Hempel. The heat circulating fireplace assembly disclosed includes a heat exchanger having a generally increased surface area to increase the heat transfer capacity of the heat exchanger.
Other heat exchangers of various designs are also employed such as is disclosed in U.S. Pat. Nos. 3,880,141, 3,896,785, 3,995,611, 3,965,886, 4,117,827, 4,008,707 and Australian Specification No. 211,350--9/54. All of these fireplace assemblies have heat exchangers and ducts for conducting air in and around the combustion chamber, however, none of these heat exchangers or ducts provides at least one secondary heat transfer surface as a means for increasing the heat transfer capacity of the heat exchanger.